A colonoscopy is an examination of the entire large intestine (colon and rectum) with a long, thin tube and attached video camera. It is often performed to screen for colorectal cancer, but may also be used to screen for and diagnose other abnormalities, such as inflammatory digestive diseases. Polyps, ulcers, pouches (diverticulosis) and narrowed areas (strictures) can all be detected during a colonoscopy. Some abnormal growths, such as polyps, can also be removed during the procedure.

The examination is performed with a lighted instrument called a colonoscope that is inserted into a patient’s rectum. The success of a colonoscopy depends greatly on a patient’s willingness to follow instructions for cleaning out the colon prior to the procedure. This is necessary to enable the physician to obtain a clear view of the colon’s interior lining.

A physician may recommend a colonoscopy if other screening tests indicate the potential presence of abnormalities in the colon. In addition, the American Cancer Society recommends colonoscopies for all men and women beginning at age 50 and every 10 years thereafter. Individuals with a higher risk for colorectal cancer may require the procedure at an earlier age or more often. However, due to patient modesty and fear of undergoing a colonoscopy, many individuals do not receive this life–saving test. It is estimated that only about half of eligible persons avail themselves of screening for colon cancer.